1. Field of the Invention
The present invention generally relates to computer apparatus and, in a preferred embodiment thereof, more particularly relates to the monitoring of a computer system's downtime due to an interruption in the electrical power supply to the system.
2. Description of Related Art
Particularly in the arena of networked computer systems it is desirable to be able to accurately determine, over a given time period, when a particular computer went "down", how long it was down, and why it went down. A computer-down condition may arise for a variety of reasons including user shut-off, a variety of error-caused shutdowns created by the computer's operating system, a shutdown automatically initiated in response to a sensed hardware failure, an automatic shutdown arising from a sensed thermal overload condition, and an outage of the electrical power supplied to the computer.
At the present time, software can be used to detect and "capture" information relating to all of these computer shutdown conditions with the exception of the power loss shutdown. The conventional method of tracking a computer's power loss shutdown is to continually "poll" some nonvolatile storage portion of the computer (such as the hard disk drive, NVRM or CMOS) to obtain, during operation of the computer, a "still running" time-stamped record which may be later used to determine the computer down time attributable to a power outage condition.
As is well known, however, this conventional requirement of repeatedly gaining polling access to, for example, the hard drive portion of a running computer to later determine when the computer was down due to a power outage typically intrudes upon the computer system to an extent which appreciably degrades its performance. It can thus readily be seen that a need exists for a nonintrusive technique for tracking a computer's downtime attributable to a power outage condition. It is to this need which the present invention is directed.